Remove global shortcuts from Electron, use WindowService for reload

[colin-grant-work]

What it does

Fixes #10701 by removing the registration of globalShortcuts from the ElectronMainApplication. There is already a command available internally to reload the window, which can be rebound or unbound and is context-sensitive, so the global shortcut is not necessary.

How to test

1. Run the Electron application
2. Open a bash terminal
3. Use the ctrl+r shortcut to access 'reverse-i-search'
4. Put focus on some element other than the terminal.
5. Use the ctrl+r shortcut to refresh the window - it should refresh
6. Dirty an editor and use the ctrl+r shortcut - you should be prompted to confirm the refresh
7. If you'd like, rebind the Refresh Window command to some other keybinding and confirm that it behaves correctly.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

I confirmed that the changes fix #10701, and when a file is dirty the reload will prevent the app from restarting unless prompted.

[vince-fugnitto]

LGTM! 👍

[orange-pig]

Sorry, I find the remove funciton 'attachGlobalShortcuts', like being refactored to theia-electron-window.ts in #10600 before time.

They are all removal operations, and there is no conflict when merging.

The problem still exists.

[kittaakos]

Did you deprecate disallowReloadKeybinding? It's not used anymore, just in tests. Thanks!